Dud detector

ABSTRACT

An apparatus for determining the condition of a top panel of a container or of a closure lid on a vacuum-packed container which indicates the vacuum or pressure condition within the container. The apparatus comprises a sensing head mounted at a detecting station for vertical reciprocation when a container is in proper position at the station which comprises a tubular housing resiliently supported in a horizontal position and enclosing a switch having an actuator intermediate the ends of the housing. The switch actuator is adapted to be operated when the housing is lowered into contact with oppositely disposed rim portions of the top panel or closure lid if the center of the panel is convex or raised, as a result of a loss of vacuum within the container. The switch controls an ejector device for removing from the detecting station a container having its top panel convex due to loss of vacuum.

United States Patent [72] inventor Henry J. Keinanen Hickory Hills, ill.[21! Appl. No. 790,275 [22] Filed Jan. 10, 1969 [45] Patented June 22,1971 [73] Assignee Continental Cm Company, Inc.

New York, NY.

[54] DUD DETECTOR 8 Claims, 4 Drawing Figs.

[52] US. Cl. 209/80, 53/53,73/52,209/88 [5i] lnt.Cl B07c 3/10 [50] Fieldof Search 209/80, 88; 73/52, 45.2, 49.3; 53/53 [561 References CitedUNITED STATES PATENTS 2,960,223 1 1/1960 Fauth 209/88 3,071,247 1/1963Paruolo 209/88 3,206,025 9/1965 Ochs ABSTRACT: An apparatus fordetermining the condition of a top panel of a container or of a closurelid on a vacuumpacked container which indicates the vacuum or pressurecondition within the container. The apparatus comprises a sensing headmounted at a detecting station for vertical reciprocation when acontainer is in proper position at the station which comprises a tubularhousing resiliently supported in a horizontal position and enclosing aswitch having an actuator intermediate the ends of the housing. Theswitch actuator is adapted to be operated when the housing is loweredinto contact with oppositely disposed rim portions of the top panel orclosure lid if the center of the panel is convex or raised, as a resultof a loss of vacuum within the container. The switch controls an ejectordevice for removing from the detecting station a container having itstop panel convex due to loss of vacuum.

PATENTEMuuemsn 3,586; 165

"FTEL 5 wvzzvmsr HENRY J. KE/NA NEN AT T' Y5.

. BUD DETECTOR This invention relates generally to the sorting ofvacuumpacked or vacuum-sealed containers and is particularly concernedwith a mechanism for detecting containers in which there has been a lossof vacuum sufficient to make it desirable to separate the container fromthe remaining containers in the packing line or the like.

it is the practice in the packaging of certain materials, for example,baby foods and similar products, to pack the product in glass jars orcontainers which are sealed with metal caps of the type having a centralpanel portion which is flexed downwardly by atmospheric pressure to alower than normal elevation or height with respect to the peripheralportion of the cap as long as the desired vacuum is maintained in thecontainer. When there is a loss of vacuum in the container due toimproper sealing or other conditions the normally flexed portion of thecap rises as it returns to an unflexed position. When this conditionexists, due to failure of the cap applying and sealing mechanism tofunction properly, or due to the presence of a defective or damagedcontainer or cap, it is desirable to separate the so-called "dud fromthe containers which have been properly sealed and in which the propervacuum condition exists. Since the processing of containers of thischaracter may be accomplished at very high speeds, ranging up to 2,000per minute, it is essential to provide a detecting mechanism which iscapable of efficient operation on containers traveling at a relativelyhigh speed. Also, allowance must be made for the presence of normallyexpected variations in the dimensions of the jars and caps sinceconsiderable tolerance is allowed in the manufacture of the same.

Various apparatus and arrangements have been developed for incorporationin a vacuum-packaging line so as to detect containers in which therequired vacuum conditions are lacking. A typical arrangement isdisclosed in RC. Bailey US. Pat. No. 3,206,027, dated Sept. 14, 1965.The apparatus disclosed in this patent is operative to detect thepresence of a sealed container in which the vacuum has been reducedbelow a predetermined minimum by measuring changes in the height of thedeflectable portions of the metal caps on the containers and detectingwhen such changes exceed a predetermined amount. This apparatus andother apparatus of this type, however, includes a sensing arm whichrides on or contacts the top surface of the container and which isrendered virtually inoperative at high speeds due to the bouncing orfluttering action which results from rapid contact of the sensing headwith successive containers. In an effort to develop apparatus which doesnot require contact with the container to measure the deflection of thetop panel, proximity sensors have been employed, which measure thedifference in height between the center panel and the margins of the topor cap and compare the same with a standard so as to detect variations.One such system or apparatus is disclosed in my U.S. Pat. No. 3,392,829,granted July 16, 1968. While this system or apparatus has beensuccessfully employed it requires the use of relatively complexcircuitry and it is expensive to install and maintain.

it is a general object of the present invention to provide an apparatusfor inspecting containers of the type in which the quality of seal andthe retention of vacuum is indicated by the position of a panel formingpart of or constituting a wall of the container wherein the device willoperate efficiently at high speed and may be installed and maintained atrelatively low cost.

it is a more specific object of the invention to provide a device forinspecting packed jars or similar containers of a type in which aflexible panel in incorporated in a wall or closure member whichindicates by its position the vacuum or pressure condition within thecontainer, which device comprises a sensing head disposed at a detectingstation which is operative to engage with the panel carrying wall of thecon-- tainer as it reaches the inspecting station and to sense the condition of the flexible panel and also an ejector device which isactuated according to the condition of the flexible panel so as toseparate from the remaining containers those containers which areimproperly sealed ordamaged or otherwise have suffered a loss of vacuum.I

.Another object of the invention is to provide a detector device forcapped jars or similar containers having a flexible panel, the positionof which indicates the presence or absence of proper vacuum conditionswithin the container, wherein an inspection head is mounted forreciprocation at an inspection station so that it may be moved intocontact with the wall of the container in which the flexible panel isincorporated and having a switch forming element which is actuated inaccordance with the condition of the flexible panel so as to activate amechanism for ejecting a container having predetermined vacuumconditions within thesame from the inspection station and separating orsegregating such containers so that they may be removed from a canningline or the like.

A still more specific object of the invention is to provide a detectordevice for sensing the condition of a flexible panel in a containerwall, the position of which indicates the pressure or vacuum conditionwithin the container, which devices comprises a tubular housingsuspended from a reciprocably mounted support which is adapted tooperate to engage the opposite ends of tubular housing with oppositelydisposed marginal portions of the container wall and having a switchoperating member intermediate the ends of the housing which is activatedupon contact with a container wall in which the indicating panel is atpredetermined elevation so as to indicate a loss of vacuum within thecontainer, which switch member is incorporated in a circuit foroperating a device whereby the defective container may be segregatedfrom the other containers.

These and other objects and advantages of the invention will be apparentfrom a consideration of the apparatus which is shown by way ofillustration in the accompanying drawings wherein:

FIG. 1 is an elevational view of an apparatus at a detecting station ina jar-packing line for detecting and ejecting vacuumpacked jars having araised center panel indicating loss of vacuum, the view being taken on avertical plane extending transversely of the path of the conveyor onwhich the jars are carried;

FIG. 2 is a cross section, to an enlarged scale, taken on the line 2-2of FIG. 1;

FIG. 3 is an elevational view, with portions broken away and to anenlarged scale, showing the sensing head of FIG. I; and

FIG. 4 is a diagrammatic layout of the electrical control circuit forthe apparatus.

For the purpose of illustration of the invention there is shown in FIG.1 a typical detecting station and a jar-packing line with a sensing head10 depending from a supporting device 12 in which there is incorporateda means for vertically reciprocating the sensing head 10, the supportingdevice 12 being in turn carried on an L-shaped bracket arm 14 adjustablymounted on an upright supporting structure 16 at the base of which thereis an ejector device 18.

The supporting structure 16 comprises an upstanding post 20 mounted on abase-fonning bracket 21 which extends beneath a top conveyor run 22 onwhich the jars or other containers C are advanced beneath the detectinghead MD. The bracket 21 may be attached to and form a part of the framestructure 23 on which the conveyor run 22 is supported as it movesbeneath the detecting head 10. The post 20 has a track formation 26 forreceiving one leg 25 of the bracket M with an adjusting screw 26 foradjusting the height of the horizontal leg 27 of the bracket 14 abovethe conveyor run 22 on which the jars C are carried. A suitable carriage28 is slidable in a track 30 in the bracket arm 27 and adjustabletransversely of the conveyor run 22 by means of a suitable adjustingscrew 31.

The ejector device 18, which may be supported on a suitable bracket atthe bottom of the post 20, is in the form of a piston 32 extending fromcylinder 33 which is supplied with operating fluid from a suitable linethrough an electrically controlled valve indicated at 34. The ejector 32is operative to move a jar C which is located at the detecting stationbeneath the detecting head 10 in a path laterally of the conveyor run 22so as to separate the same from the jars which are permitted to remainon the conveyor 22.

The detecting head 10 (H6. 3) comprises a housing 40 which is formed ofa suitable plastic material, such as, for example, Synthane" tubing,which is understood to be a laminate of plastic and glass fiber or thelike, produced by Synthane Corp. of Oaks, Penna, and which hasnonconducting electrical characteristics. The housing 40 is in the formof a length of the cylindrical tubing and has an axial dimension greaterthan the diameter of the maximum size container end which is to betested by the equipment. The tubular housing 40 is of sufficientcross-sectional diameter to enclose a leafspring-mounted switch contactAll with the leaf spring 42 secured at one end to a contact member 43and extending in the axial direction in the housing 40, with the otherend normally spaced from a fixed contact member 44 which depends from acontact or connector 45. The bottom wall of the tubular housing 40 hasan aperture 46 located intermediate the tube ends 17 and 48 in whichthere is disposed a switch actuator in the form of a headed pin 50 withthe stem portion thereof slidably mounted in the aperture 45. The pin 50is adapted to engage the switch contacts 41 and when it is depressed bycontact with the top of a raised center panel P in a jar top or closurecap T. When the center panel P is concave, as indicated in FIG. 3, thepin 50 is inoperative and the switch contacts 41 and 44 remain open. Thehousing 40 is, of course, formed of nonconducting material or the switchcontacts are suitably insulated.

The tubular housing 410 is suspended by means of a length of spring wire51, for example, a length of relatively stiff resilient piano wire. Thewire 51 depends from the end of a leaf spring 52 which extends from thecarriage support member 28 and through a vertically disposed centralopening 53 in a cylindrical soft iron center portion 54 of a magnetassembly 55 which includes permanent magnet ring 55' and which issupported on the carriage 28. A moving coil 56 is carried on the leafspring 52 which forms with the magnet assembly 55 a loudspeakentypemotor device adapted to impart to the depending wire 51 and the tubularhousing as a vibrating motion in a vertical path. A leaf spring member57 also extending from the carriage support 28 steadies the wire 51 andcooperates with the member 52 in supporting the tubular housing 40. Thecoil 56 is actuated or drawn down by an electrical impulse from thecapacitor discharge power supply as indicated schematically in FIG. 5,with the springs 52 and 57 returning the coil 56 to the up positionafter it is depressed by an impulse from the power supply.

The activation of the coil 56 is controlled by a jar detector switch,indicated at 60 in FIG. 1, which is mounted at the detecting station andwhich may be a proximity-type switch actuated by the presence of acapped jar C at the station which is in proper position for contact bythe tubular housing d when the latter is lowered by an impulse operatingthe coil 56.

Referring to FIG. 4, the presence of a container C at the detectingstation generates a pulse for operating the coil 556. The switchmechanism carried in the cylindrical housing 40, which includes thenormally open contacts 41 and 44), is incorporated in a conventionalcircuit for actuating or operating the ejector mechanism for rejectplunger 32.

In the operation of the device, when a container C reaches the detectorstation and is in predetermined position thereon the switch 60 closesthe circuit for supplying an impulse current to the coil 56, resultingin the lowering of the tubular housing 40 so that it contacts the top ofthe closure on the container at the points indicated at 611 and 62 onFIG. 3. The contact with the container closure or cap T is momentary andthe tubular housing 40 is raised to its normal position by the leafsprings 52 and 57. The downward motion and engagement of the housing 40with the container top T will engage the switch-operating button 50 withthe raised portion of the center pane-ll? when there has been a loss ofvacuum sufficient to bring the same above a predetermined level relativeto the top surface of the container, that is, when the panel I? isconvex on its top surface. When button 50 is raised the switch contacts41 and 44 are closed and the plunger 32 is actuated to eject thedefective container at the detecting station. The coil 56 which producesa constant downward force will take care of variations in the overallheight of the container and closure member so as to allow for variationsin cap orientation and manufacturing tolerances in the jar height. Thecontact of the tubular housing 40 with a top of a container is of verysmall duration so that there is no interference with the movement of thecontainer on the conveyor 22. Also, the weight of the housing 40 and theassociated parts is very small and with low inertia mass a very fastresponse rate can be obtained by utilizing reciprocating motion such asprovided by the pulse motor arrangement.

I claim:

1. Means for sensing contour variation of closure members on sealedcontainers as they are advanced along a path, one by one, past adetecting station and for ejecting certain of said containers from saidpath, which means comprises a sensing head, a resilient support at saiddetecting station for mounting said sensing head for reciprocation in avertical path, said sensing head having a housing in the form of arelatively short section of tubing disposed with the longitudinal axisthereof extending crosswise above the path of said containers so thatlowering said head will engage end portions of said housing withoppositely disposed top marginal portions of a container top wall whenthe container is at said detecting station and the top wall is inacceptable condition with the center portion thereof concave, meansresponsive to positioning of a container at said detecting station forlowering said housing so as to momentarily engage said housing with saidcontainer top wall, and a switch-actuating member extending from thebottom of the housing intermediate the end portions thereof which isoperated upon engaging with the center portion of the top wall of acontainer positioned at said station when said center portion is raiseda predetermined amount so that it is not in acceptable condition, meansat said detecting station for ejecting containers which are not inacceptable condition and electrical control means for said ejectingmeans which is operative in response to operation of saidswitch-actuating member.

2. A device for sensing contour variation of closure members on sealedcontainers as they are advanced along a path, one by one, past adetecting station which comprises a sensing head, a support on whichsaid head is mounted for reciprocation in a vertical path at saiddetecting station, said sensing head including a housing in the form ofa relatively short section of tubing disposed with the axis thereofextending crosswise above the path of said containers so that loweringsaid head will engage axially spaced end portions of said housing withoppositely disposed top marginal portions of a container top wall when acontainer is at said detecting station with the top wall having a centerportion thereof concave, electrical impulse means operative to lowersaid head into momentary engagement with the top of a container at saiddetecting station, container-sensing means at said detecting station foractuating said electrical impulse means when a container is positionedat said station, switch elements enclosed in said tubular housing and aswitch-actuating member extending from the bottom of said tubularhousing intermediate the container-engaging end portions thereof whichis inoperative when the housing is engaged with a container having a topwall with a center portion thereof concave and which is operated uponengaging with the center portion of the top wall of a container in whichsaid center portion is raised to a convex position.

3. An apparatus as set forth in claim 2 and said head being mounted independing relation on a resilient member which permits said head to belowered into contact with variable height containers.

4. In an apparatus for detecting defective vacuum-packed containers ofthe flip-panel-type in which loss of vacuum within the container isindicated by a raised panel portion in the top wall of the container, adetecting head comprising a length of tubing having a switch mountedtherein with an actuator mounted in the bottom wall intermediate theends of the tubing, a support means for mounting said tubing with thelong axis thereof extending crosswise above the path of advance of aline of containers which support means includes resilient means normallyholding said head above the path of the containers, and meanscooperating with said support means for reciprocating said tubing in avertical path so as to bring opposite end portions of said tubing downinto momentary engagement with oppositely disposed portions of the topof successive containers thereby positioning said switch actuator foroperation by an indicator panel portion where the latter is in raisedposition due to improper sealing and resultant loss of vacuum in thecontainer.

5. In an apparatus as set forth in claim 4 and said length of tubingbeing formed of a substantially rigid plastic having nonconductingelectrical characteristics.

6. In an apparatus as set forth in claim 4 and means at said station fordetecting the presence of a container, and electrical impulse means forreciprocating said tubing which is responsive to operation of said meansfor detecting the presence of a container at said detecting station.

7. In an apparatus as set forth in claim 4 wherein said support meanscomprises vertically spaced leaf spring members extending laterally ofthe path of vertical reciprocation of said head and said means forreciprocating said tubing comprises electrical impulse means actuated inresponse to positioning a container at said detection station.

8. In an apparatus for detecting defective vacuum-packed containers ofthe flip-panel-type in which loss of vacuum within the container isindicated by a raised panel portion in the top wall of the container, adetecting head comprising a length of tubing having a switch mountedtherein with an actuator mounted in the bottom wall intermediate theends of the tubing, a support for mounting said tubing with the longaxis thereof extending crosswise above the path of advance of a line ofcontainers, means for reciprocating said tubing in a vertical path so asto bring opposite end portions down into engagement with oppositelydisposed portions of the top of successive containers therebypositioning said switch actuator for operation by an indicator panelportion where the latter is in raised position due to improper sealingand resultant loss of vacuum in the container, said support for mountingsaid length of tubing including a relatively stiff resilient wirelikemember which depends from said means for reciprocating said tubing andsaid means for reciprocating said tubing being operable to accommodatewithin predetermined limits variations in the height of the containers.

1. Means for sensing contour variation of closure members on sealedcontainers as they are advanced along a path, one by one, past adetecting station and for ejecting certain of said containers from saidpath, which means comprises a sensing head, a resilient support at saiddetecting station for mounting said sensing head for reciprocation in avertical path, said sensing head having a housing in the form of arelatively short section of tubing disposed with the longitudinal axisthereof extending crosswise above the path of said containers so thatlowering said head will engage end portions of said housing withoppositely disposed top marginal portions of a container top wall whenthe container is at said detecting station and the top wall is inacceptable condition with the center portion thereof concave, meansresponsive to positioning of a container at said detecting station forlowering said housing so as to momentarily engage said housing with saidcontainer top wall, and a switch-actuating member extending from thebottom of the housing intermediate the end portions thereof which isoperated upon engaging with the center portion of the top wall of acontainer positioned at said station when said center portion is raiseda predetermined amount so that it is not in acceptable condition, meansat said detecting station for ejecting containers which are not inacceptable condition and electrical control means for said ejectingmeans which is operative in response to operation of saidswitch-actuating member.
 2. A device for sensing contour variation ofclosure members on sealed containers as they are advanced along a path,one by one, past a detecting station which comprises a sensing head, asupport on which said head is mounted for reciprocation in a verticalpath at said detecting station, said sensing head including a housing inthe form of a relatively short section of tubing disposed with the axisthereof extending crosswise above the path of said containers so thatlowering said head will engage axially spaced end portions of saidhousing with oppositely disposed top marginal portions of a containertop wall when a container is at said detecting station with the top wallhaving a center portion thereof concave, electrical impulse meansoperative to lower said head into momentary engagement with the top of acontainer at said detecting station, container-sensing means at saiddetecting station for actuating said electrical impulse means when acontainer is positioned at said station, switch elements enclosed insaid tubular housing and a switch-actuating member extending from thebottom of said tubular housing intermediate the container-engaging endportions thereof which is inoperative when the housing is engaged with acontainer having a top wall with a center portion thereof concave andwhich is operated upon engaging with the center portion of the top wallof a container in which said center portion is raised to a convexposition.
 3. An apparatus as set forth in claim 2 and said head beingmounted in depending relation on a resilient member which permits saidhead to be lowered into contact with variable height containers.
 4. Inan apparatus for detecting defective vacuum-packed containers of theflip-panel-type in which loss of vacuum within the container isindicated by a raised panel portion in the top wall of the container, adetecting head comprising a length of tubing having a switch mountedtherein with an actuator mounted in the bottom wall intermediate theends of the tubing, a support means for mounting said tubing with thelong axis thereof extending crosswise above the path of advance of aline of containers which support means includes resilient means normallyholding said head above the path of the containers, and meanscooperating with said support means for reciprocating said tubing in avertical path so as to bring opposite end portions of said tubing downinto momentary engagement with oppositely disposed portions of the topof successive containers thereby positioning said switch actuator foroperation by an indicator panel portion where the latter is in raisedposition due to improper sealing and resultant loss of vacuum in thecontainer.
 5. In an apparatus as set forth in claim 4 and said length oftubing being formed of a substantially rigid plastic havingnonconducting electrical characteristics.
 6. In an apparatus as setforth in claim 4 and means at said station for detecting the presence ofa container, and electrical impulse means for reciprocating said tubingwhich is responsive to operation of said means for detecting thepresence of a container at said detecting station.
 7. In an apparatus asset forth in claim 4 wherein said support meaNs comprises verticallyspaced leaf spring members extending laterally of the path of verticalreciprocation of said head and said means for reciprocating said tubingcomprises electrical impulse means actuated in response to positioning acontainer at said detection station.
 8. In an apparatus for detectingdefective vacuum-packed containers of the flip-panel-type in which lossof vacuum within the container is indicated by a raised panel portion inthe top wall of the container, a detecting head comprising a length oftubing having a switch mounted therein with an actuator mounted in thebottom wall intermediate the ends of the tubing, a support for mountingsaid tubing with the long axis thereof extending crosswise above thepath of advance of a line of containers, means for reciprocating saidtubing in a vertical path so as to bring opposite end portions down intoengagement with oppositely disposed portions of the top of successivecontainers thereby positioning said switch actuator for operation by anindicator panel portion where the latter is in raised position due toimproper sealing and resultant loss of vacuum in the container, saidsupport for mounting said length of tubing including a relatively stiffresilient wirelike member which depends from said means forreciprocating said tubing and said means for reciprocating said tubingbeing operable to accommodate within predetermined limits variations inthe height of the containers.